BIOMECHANICS (PART3)

Question 1

what is Biomechanics ?

Answer 1

Biomechanics is the study of human movements, the effect of force and motion on a sport performance.

Question 2

What are Newton’s laws?

Answer 2

Law of inertia, Law of acceleration and Law of reaction.

Question 3

What is stated in Newton’s first law?

Answer 3

Law of inertia, A body remains at rest or uniform velocity until an external or unbalanced force acts upon it.

Question 4

What is stated in Newton’s second law?

Answer 4

Law of acceleration, A body’s rate of change in momentum is proportional to the size of force applies and acts in the same direction as the force applies.

Question 5

What is stated in Newton’s third law?

Answer 5

Law of Reaction, when 2 body’s come into contact with each other there is an equal and opposite reaction force.

Question 6

What are the 4 different concepts that can be calculated?

Answer 6

Velocity, Momentum, Acceleration, force.

Question 7

What is the formula for Velocity and Momentum?

Answer 7

Velocity=displacement/time taken

Momentum=Mass X Velocity

Question 8

What is the formula for Acceleration and Force?

Answer 8

Acceleraration= (final velocity - initial velocity)/time taken

Question 9

What are the units for the 4 main concepts that can be calculated?

Answer 9

Velocity= m/s
momentum= kgm/s
Acceleration= m/s/s
Force= Newtons (N)

Question 10

what is force and its doing?

Answer 10

Essential for motion, external and internal forces act on a body that tend to alter a body’s state of motion.

Question 11

External force?

Answer 11

is an outside force that acts on the body, e.g. friction, air resistance, weight (gravity), reaction.

Question 12

Internal force?

Answer 12

Generated from within the body, when the skeletal muscle contract .
example; (100m sprinter contracts rectus femoris to extend knee and gastrocnemous to planter flex the ankle to generate force needed to drive away).

Question 13

What is Net force and when is Net force = 0?

Answer 13

Net force is the overall motion of the body taking HORIZONTAL and VERTICLE forces into count. Net force = 0 when the overall motions have no change in it and all force are balanced.

Question 14

When is Net force unbalanced?

Answer 14

Net force is unbalanced when there is change in motion and the external force acting on a body are unbalanced. During this situation of a body there will be acceleration, deceleration, change in shape and direction.

Question 15

Example of when Net force is balanced and unbalanced.

Answer 15

Net force balanced; in rugby 2 packs are in scrum with equal weight(Net force = 0)

Net force unbalanced; in tennis serve the player generates greater force then needed to over come the tennis ball’s inertia.

Question 16

how does Analysis through use of technology help sports?

Answer 16

professionals uses it to analyse movement and enhance performance.

Question 17

What is Limb Kinematics?

Answer 17

Is the study of movements in relation to time and space.

Question 18

How does Limb kinematics analyse’s movements.

Answer 18

reflective markers are placed on the body’s joints to which can be traced by the infra-red camera’s and convert into digital format. To evaluate the joint and limb efficiency with measurements of bones geometry, displacement, velocity and acceleration in multiple planes of movements.

Question 19

Disadvantages of limb kinematics.

Answer 19

too expensive.
doesn’t account for individual difference.
Limited to lab conditions

Question 20

Advantages of Limb kinematics?

Answer 20

Immediate anaylsis recieved
abjective measurements
accurate data

Question 21

What is force plate?

Answer 21

It can measure ground reaction force of athletes, balancing, running or jumping.

uses transducers to measure the force involved in during motion.

Question 22

How does force plates work?

Answer 22

upon coming into contact with force plate it will display the time and force that is being applied on a graphical form of computer..

Question 23

Advantages of force plates?

Answer 23

Reliable results are provided.
Can prevent injuries
Helps with generating the force needed for every contact point e.g. in verticle jump both legs need to generate the same Newtons of force.

Question 24

Disadvantages of force plate?

Answer 24

Too expensive
limited to lab conditions
maintenance/specialist training required.

Question 25

What is Reliability?

Answer 25

the extent to which an experiment, test, or measuring procedure gives the same result after repeated trails.

Question 26

What is validity?

Answer 26

How well a test measures what it claims to measure.

Question 27

What is Validity and Reliability purpose?

Answer 27

The purpose of establishing reliability and validity in research is essentially to ensure that data are sound and replicable, and the results are accurate.

Question 28

What are Wind tunnels?

Answer 28

Are aerodynamic tunnels that help to improve the the movement of air around an object e.g. F1 car.

Question 29

Advantages of Wind tunnels?

Answer 29

Accurate and Reliable data, Good for performance analysis, Can control environmental variables.

Question 30

Disadvantages of wind tunnels?

Answer 30

Very expensive to buy. Take lots of space due its size. Needs specialists to function it. The analysis are very complex.

Question 31

Center of mass definition.

Answer 31

Centre of is the point at which the forces are balanced in all directions or from where gravity acts from

Question 32

Stability definition.

Answer 32

The ability for a body to resist motion and remain at rest. + It is also the ability to withstand applied force and return to original position.

Question 33

factors that effect stability.

Answer 33

Mass of Body, Height of centre of mass Base of Support, Line of Gravity

Question 34

How can unstability be advantagous.

Answer 34

Changing direction, Rotating, Increasing the range of motion or stretching

Question 35

How to minimise stability?

Answer 35

Stability is minimised when the force acting on body are unbalanced and the body has gained motion.

Question 36

How to maximise stability?

Answer 36

Low body position (gives low centre of mass) Large Base of support Having multiple contact points Line of gravity close to Base of support Larger mass

Question 37

What is Lever system?

Answer 37

Is the co-ordination of our bones and muscles, to create human movement.

Question 38

Function of lever system?

Answer 38

Generate muscular effort to overcome a given load Increase the speed of a given movement

Question 39

Name the 4 components of Lever System.

Answer 39

Lever=Bone Fulcrum=Joint Load=weight or resistance Effort=muscular force

Question 40

What is a Lever?

Answer 40

A rigid structure which rotates around a fixed point.

Question 41

what is the fixed point where the Lever rotates?

Answer 41

fulcrum(joints)

Question 42

when is effort created?

Answer 42

when the muscles surrounding the joint contracts and the force is generated.

Question 43

Why is the force needed?

Answer 43

To overcome a given load.

Question 44

Example of Lever;

Answer 44

Radius and Ulna

Question 45

Example of Fulcrum;

Answer 45

Elbow joint

Question 46

Example of Effort;

Answer 46

Force created by biceps brachii

Question 47

Example of Load;

Answer 47

holding weights in hand during bicep curls

Question 48

Classification of levers

Answer 48

First class levers Second class levers Third class levers

Question 49

components and example of first class lever;

Answer 49

COMPONENT; fulcrum is in the middle * E - F - L or L - F - E EXAMPLE extention of the head when preparing to header the ball

Question 50

components and example of Second class lever;

Answer 50

COMPONENT; Load is in the middle * F - L - E or E - L - F EXAMPLE Ball of the foot in the take off phase of high jump

Question 51

components and example of third class lever;

Answer 51

COMPONENT; Effort is in the middle * F - E - L or L - E - F EXAMPLE Flexion of the elbow during bicep curl

Question 52

Efficiency of the lever system is the......(what?)

Answer 52

is the order and distance of lever components from the fulcrum; *Distance of Fulcrum > Effort == Effort arm *Distance from Load > Fulcrum == Load arm

Question 53

What give a lever system Mechanical advantage or Mechanical disadvantage?

Answer 53

The length of the Effort or Load arm.

Question 54

True or False in second class lever the effort arm is always greater than the Load arm.

Answer 54

True

Question 55

What Mechanical Advantage? which class lever has it?

Answer 55

Mechanical advantage is where the Effort arm is greater than the Load arm. *Second class lever

Question 56

What Mechanical disadvantage? which class lever has it?

Answer 56

Mechanical disadvantage is where the Load arm is greater than the Effort arm. *Third class lever

Question 57

What does Mechanical Advantage do?

Answer 57

Allows you to move larger load with relatively small force.

Question 58

What does Mechanical disadvantage do?

Answer 58

Larger Effort is required to move relatively small load.

Question 59

positive and negative of Second class lever or Mechanical advantage;

Answer 59

Positive; *larger load is moved with small force negative; *at the expense of velocity

Question 60

positive and negative of third class lever or Mechanical disadvantage;

Answer 60

positive; *moves the load at high velocity *generate greater acceleration over larger range of motion Negative; *Need greater effort than load